156 MORPHOLOGY AND EVOLUTION
13* A small internal lateral ligament.
i,4» A band from the back of the distal radio-carpal j.jint to the os magnum,
15} A band from the back of the radius to the cuneiform and uncinate bones.
'6) Three interosseous ligaments.
The cavity of the joint (fig. 35, B) is complicated. The distal end of the radius has two facets for articulation with the scaphoid and semilunar bones; and a strong ligament runs from the distal end of the ulna to the os pisiforine, which is large. The synovial cavity between the radius and the scaphoid and semilunar bones is prolonged into the inferior radio-ulnar joint and the joint between the cuneiform and pisiform bones. A large synovial cavity separates the head of the os magnum from the scaphoid, semilunar, cuneiform and unciform bones, and is continuous with the cavitv between the
scaphoid and trapezoid bones. This transverse carpal cavity is prolonged distally on both sides of the os magnum; it is continuous with the carpo-metacarpal cavity. The intermetacarpal joints have prolongations of the carpo-metacarpal cavity, and interosseous ligaments connect the metacarpals to one another.
The metacarpo-phalangeal, interphalangeal and pollical joints are much as in Man.
Hip-joint.—Keith (96) points out that the ilio-femoral, ischio-femoral and pubo-femoral ligaments are more prominent than in Man, but in one Chimpanzee the only differentiated band was the anterior part of the ilio-femoral ligament. The ligamentum teres is usually present in all Apes except the Orang, which has none.
Knee-joint (fig. 36, F).~-The following account of